Fig3_10 Balmer line of hydrogen

Fig. 3.10 . The spectrum of the Sunís optically visible light exhibits four strong absorption lines that are attributed to hydrogen whose line wavelengths are spaced closer together at shorter wavelengths (top). These lines are designated H? at a red wavelength of 656.3 nm, H? at a wavelength of 486.1 nm, H? at the blue 434.1 nm and H? at the violet 410.2 nm, where one nanometer = 1 nm = 10-9 m. These spectral features originate when an electron in a hydrogen atom moves from a low to high electron orbit, whose orbital energy is a function of the integer n (bottom). They have been named the Balmer lines after the Swiss mathematics teacher Johann Balmer (1825?1898) who first derived an equation in 1895 that describes their wavelengths in terms of integers.